To my knowledge, +1 to hit on a weapon is the same as +1 to hit as class bonus.
I dont know the actual formula (I knew it once but forgot). All I remember is that, compared to other games, it is almost impossible to get into a situation where you dont hit, both as attacker and as target.

The only exception I can think of is an added extra deep area in ToME2 ("nether realm"), where they just inflated monster stats (even in normal dungeons, its called "levelling" monsters, so a hill orc might get something like +2 speed, +10 to hit and AC or whatever, depending on dungeon depth). This levelling process, when applied at a depth of 200 or so, creates amounts of AC that are actually very hard to hit. So a typical attack round of a fighter with 30 attacks (yes, you can get that many in that game) would have something like 28 misses and 2 hits.

This formula is the main reason why damage rings are better than to hit rings and robes of resistance are better than plate mail +10.

So a hobbit priest, or say a gnome mage, should be as good at landing hits with a weapon %age wise (ignoring # blows difference) as a half-troll warrior in the end game, assuming maxed str/con/dex?

No. Mages have lousy gains in their accuracy compared to warriors, so warriors naturally become more accurate over time relative to mages. I don't feel like trying to quantify this, but my guess would be that an accurate warrior could reach 80% accuracy or maybe a bit better against Morgoth, while an accurate mage would probably be more around 70%.

No. Mages have lousy gains in their accuracy compared to warriors, so warriors naturally become more accurate over time relative to mages. I don't feel like trying to quantify this, but my guess would be that an accurate warrior could reach 80% accuracy or maybe a bit better against Morgoth, while an accurate mage would probably be more around 70%.

It sure "feels" like a mage or a priest can barely hit squat, and that the bless prayer/scroll makes a significant difference in a them landing blows, while the warrior barely ever misses.

In the character generation screen, a Hobbit mage has "hit +24" while a Half-Troll Warrior has "hit +90". It sure does feel like the HT warrior lands > 3x more blows. I was just wondering if this "to hit" scale is the same one that weapon magical to-hit participates in, or if those scales are different (since on the character info screen is lists two separate "base, bonus" to hit

In the character generation screen, a Hobbit mage has "hit +24" while a Half-Troll Warrior has "hit +90". It sure does feel like the HT warrior lands > 3x more blows. I was just wondering if this "to hit" scale is the same one that weapon magical to-hit participates in, or if those scales are different (since on the character info screen is lists two separate "base, bonus" to hit

They're certainly related, but I'm pretty sure it's not just like half-troll warriors having the equivalent of a +66-to-hit invisible modifier. In other words, the accuracy score on the character screen factors into your accuracy but in a different way from equipment bonuses do.